Research On The Key Issues In Mobile Ad Hoc Networks

As a convenient wireless access method, mobile Ad Hoc network has aroused the interests of more and more people. The wireless multiple access technologies and routing protocol have become research hotspots and greatly attracted the attention of academic researchers. With the rapid development of wireless high speed data service, developing a medium access protocol and routing protocol under the limited bandwidth with higher throughput and lower energy consumption is a challenge work.The research work in this dissertation carries a deep study on new techniques of MANET and put emphasis on the multiple access and routing protocols to support the integration of code division medium access (CDMA) and directional antennas with MANET. The major achievements and results are outlined as follows.1. A single busy tone code division multiple access (SBT-CDMA) protocol is proposed for CDMA-based mobile ad hoc network. The RTS/CTS handshake mechanism, busy tone and power control are integrated with CDMA to improve the network performance. The RTS/CTS dialogue is used for the CDMA-code allocation and exchange of the power control information. Base on the difference between the calculation value and measurement value of the received busy tone power, a node can ascertain whether could initialize a RTS packet transmission. Simulation results show that SBT-CDMA can significantly reduce the packet collision and increase the network throughput with lower energy consumption, and the near-far problem in CDMA network is also overcame.2. For directional antennas applications in mobile Ad Hoc networks, a busy tone and directional multiple access protocol with power control (BT-DMACP) is proposed. The directional hidden terminal problems and side lobe interference for the network using directional antennas are considered. Through directional busy tone signals and the power control method, the directional transmission power of data packets can be adjusted in time. In order to estimation of the maximal interference power supported by receiving node, an adaptive...